Unless otherwise stated, MetaLab and its datasets are licensed under a Creative Commons Attribution 4.0 International License, CC BY 4.0. If you use MetaLab in a derivative work, you must give credit, but otherwise you are free to do anything else you want with most products from the site. Some datasets listed under the Contributors page may be marked with a CC BY NC License 4.0 logo. This means these particular datasets are licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, CC BY-NC 4.0. These datasets may not be used for commercial purposes but otherwise are free to use and adapt as long as credit is given.
MetaLab is written almost entirely in R, using a combination of RMarkdown and Shiny.